Gas-generating compositions containing
hydroxyl ammonium oxalate coolants
and method for their preparation



United States Patent 26,468 GAS-GENERATING COMPOSITIONS CONTAININGHYDROXYL AMMONIUM OXALATE COOLANTS AND METHOD FOR THEIR PREPARATIONErnest S. Sutton, Jr., Newark, Del., assignor to Thiokol ChemicalCorporation, Bristol, Pa., a corporation of Delaware No Drawing.Original No. 3,193,421, dated July 6, 1965,

Ser. No. 266,497, Mar. 20, 1963. Application for reissue Jan. 24, 1967,Ser. No. 617,429

24 Claims. (Cl. 14919) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE Curable gas generating compositions composedessentially of hydroxyl ammonium oxalate as a coolant, a p rchloratesalt oxidiz r, a combustible fuel binder, and optional propellantadjuvants such as plasticizers, ballistic agents, hygroscopicityinhibitors, or combustion catalysts.

This invention relates to solid fuel compositions useful, for generatinggas upon combustion and to methods for utilizing these compositions.

More particularly this invention concerns the addition of hydroxylammonium oxalate to perchlorate based gas generating compositions toimprove their combustion characteristics so that they can be used forgas turblue and jet engine applications.

The novel coolant of this invention has the structure:

HONHsOC O HO NHzO =0 Hydroxyl ammonium oxalate is prepared according tothe method described by P. F. Tryon in pages 83-85, vol. III, InorganicSynthesis 1950, First Edition, published by McGraw-Hill Book Company,Inc. of New York.

Within recent years, especially where applications in the aerospace oraeronautical fields are concerned, there has been an increasing relianceupon the use of devices driven or activated through the generation ofgases. These devices commonly derive their energy from the controlledcombustion of solid gas generating composi tions in the gas turbineengines. The combustion of these solid compositions to gaseous productscan be used to pressurize a fluid or drive a turbine to producemechanical or electrical energy or to start various mechanical devices.The gas-generating devices are particularly advantageous in that theyare capable of producing a rather substantial amount of powerconsidering the relatively light weight of the fueled gas generatorcompared to conventional gas or oil powered generators. Because of theirhigh power to low weight ratio, these devices are especially suited todrive gas turbines and jet type engines for intermitent or short termuse.

In some respects, gas generating compositions are similar to solidpropellant compositions used to power rockets and missiles. Like missilepropellant compositions, gas generating compositions must fulfillcertain stringent physical requirements to be acceptable. For example,like missile propellant compositions, gas generating compositions mustbe ballistically stable after prolonged storage at extreme temperaturesranging from as high as 180" F. to as low as -80 F. In addition,particularly for aerospace and military applications, the compositionsmust be readily ignitable within these same tem- "ice perature ranges.Furthermore, the compositions must be relatively insensitive to shock,be homogeneous in content, have substantial elasticity to minimize gapsor voids and must burn evenly and consistently. Finally, both types ofcompositions consist essentially of an oxidizer and a combustible fuelbinder ordinarily supplemented by small quantities of various adjuvants.It should be mentioned that the adjuvants are optional components to thecomposition and will vary in type and content from composition tocomposition.

While as indicated above there are several areas of similarity betweengas generating compositions and propellant compositions, the differencebetween the two types of compositions are even more significant. Forexample, while an oxidizer is also an integral part of a gas generatingcomposition, the requirements for this oxidizer differ considerably fromthose used in missile propellants and in some respects the requirementsare even more severe. Namely, the oxidizer in gas generatingcompositions unlike oxidizers in propellant compositions, must have arelatively slow burning rate and burn at relatively low flametemperatures. Another important requirement is that the combustion ofthese gas generating compositions evolve essentially particle free gasesthat are relatively nonerosive. In addition, ideally the burning rate ofthe gas generating composition should be as independent as possible ofthe temperatures and pres sures produced during combustion. The need forthese special requirements arises because of the different purposes forwhich the two compositions are designed. For example, the combustion ofmissile propellants produces exceedingly high flame temperatures, oftenin excess of 4000 F. These high flame temperatures are destructive toparts fabricated of the common commercial metal alloys such as thestainless steels over any sustained period of time. In fact, prolongedexposure to these higher temperatures attack many of the speciallyformulated so salled heat resistant alloys." However, the erosion andcorrosion of the metal missile parts that occurs during combustion is oflittle importance in missiles since they are designed as expendableone-shot pieces of hardware.

For the same reasons the presence of erosive or corrosive combustionproducts as evidenced by smoky combustion gases causes little concern.However, the effect that high combustion temperatures and erosive solidparticles in the combustion gases have on gas turbine-type engines isfar more serious. For example, the solid particels not only erode themetal parts they contact but they can clog the movable engine partsimpairing performance as well as causing engine failure. This increasesmaintenance costs and reduces useful engine life. Since power generatingdevices are designed for long term use, dependability and long life areessential for commercial acceptance. Thus, the typical perchlorate-basedpropellant composition of the prior art have had little value as gasgenerating compositions.

That unmodified missile propellant compositions and gas generatingcompositions are not interchangeable has been established in the priorart. This is particularly the case in perchlorate based propellants.Perchlorate oxidizers are not only much more energetic than those usedin gas generating compositions but also offer other importantadvantages. For example, the burning rate of perchlorate oxidizers isrelatively independent of their temperature and pressure at combustion,whereas the burning rate of ammonium nitrate, a commonly used oxidizerin gas generating compositions is much more dependent upon thetemperature and pressure. A further advantage that these oxidizersposess over ammonium nitrate is that they contain more oxygen. Thehigher oxygen content of the perchlorates tends to favor a smoother andmore continuous combustion than is possible with ammonium nitrate.

In spite of the significant advantages that can be ob tained whenperchlorate-based oxidizers are used in gas generating compositions,little progress has been made in the preparation of perchlorate-basedgas generating compositions because of a serious shortcoming thatperchlorates possess for this purpose. This is the production oftemperatures above 4000 F. This high flame temperature causes dilficultyin both the construction and maintenance of gas generating devices. Itwould therefore be an important advance in the art to significantlyreduce the flame temperature of perchlorate-based propellantcompositions so that they can be used in gas-genertaing engines anddevices.

Thus it is an object of this invention to convert previuuslynon-utilizable missile propellant compositions into gas generatingcompositions useful for broader fields of application. These includecompositions useful for actuating and powering mechanical devices, andturbine and jet engines among others.

Another more specific object of this invention is to convert highlyenergetic perchlorate based missile propellant compositions into usefulgas generating composi- I tions.

Yet another object of this invention is to prepare ballistically stablegas generating compositions whose burning rate is relatively independentof combustion temperatures and pressures.

Yet a further object of this invention is to prepare solid gasgenerating compositions whose combustion is not only smooth andcontinuous but produces lower flame temperatures than has been possiblewith other gas-generating compositions of the prior art.

Finally it is an object of this invention to prepare a novel class ofperchlorate based gas generating compositions heretofore unknown to theart.

Other objects will become apparent to those skilled in the art from aconsideration of the folowing detailed description.

As the result of an extended investigation, it has been discovered thatthe objects set forth above can all be accomplished by means set forthbelow.

In practice a novel and superior gas generating composition is preparedby mixing, casting, and curing the hydroxyl ammonium oxalate coolant ofthis invention with (1) an oxidizer (2) a combustible fuel binder withor without (3) propellant adjuvants or conditioning agents.

The gas-generating composition of this invention con- 7 sistsessentially of from about l[70]60% by weight of hydroxyl ammoniumoxalate preferably above 20% by weight mixed with:

(1) From about 20-[80175 by weight of an inorganic perchlorate oxidizerpreferably ammonium perchlorate. However, the alkaline earth metalperchlorates and the alkali metal perchlorates are satisfactory.

(2) From about 15-35% by weight of a combustible fuel binder. Thecombustible fuel binder always includes a major amount of a polymericcomposition and a minor amount of one or more curing agents. Thepreferred binders are the polyesters particularly the modifiedpolyesters such as the carboxy-terminated linear polyesters, thepolyester-polyurethane eompolymers and the polyester-polyurethanepolymers terminated with thiol groups. Other polymers which can be usedare the polycarbonates, polyurethanes, the polyacrylates, thepolyepoxides as well as the copolymers of one or more of these.

(3) Up to 10% by weight of a propellant adjuvant. As indicated earlierthe presence of propellant adjuvants while not essential to theoperability of the inventive gas generating compositions, are preferableto achieve optimum performance. Where such an adjuvant is used, it willordinarily comprise between 0.25-5% by weight of the inventive gasgenerating composition and will seldom Cit comprise more than by weightof the gas-generating composition.

The above components of the gas generating mixture are mixed to form ahomogeneous composition then cast or extruded, and cured using theprocedures well known in the gas generator art so that they will burnevenly and continuously within the gas generator.

( 1) OXIDIZER As indicated earlier the perchlorate oxidizer, combustiblefuel binder and propellant adjuvants can be varied both as to contentand choice. For example, numerous perchlorates including the alkalineearth metal perchlorates, the alkali metal perchlorates, the metallicperchlorates generally and ammonium perchlorate can be used asoxidizers. However ammonium perchlorate is the favored perchlorateoxidizer primarily [fecause] because it produces more fully gaseousproducts during combustion than do the other perchlorates. In addition,it is available in large quantities in a high state of purity at lowcost.

In general, varying proportions of the oxidizer can be employed in thegas generating compositions of this invention. For example, dependingupon the use intended, the oxidizer can be present in the cured solidgas generating composition in sufficient quantity so that it makes up[80]75% by weight of the finished compositions.

Compositions containing the lower percentage of oxidizer, in the rangeof 20-50%, have a lower burning rate and thus would be useful for gasturbine and jet aircraft starters; whereas the compositions containingthe higher percentage (about [80]75% of oxidizer would be useful inpreparing gas generating compositions where a higher burning rate isdesirable. In all instances, the balance of the gas generatingcomposition will consist of [20110- by weight of the inventive coolantand 15-35% by weight of fuel binder with up to 10% by weight of one ormore propellant adjuvants if desired.

(2) FUEL BINDER The fuel binder referred to throughout this applicationrefers to combustible polymeric resins or their precursors which can becured to the desired hardness and which are utilized as fuels for theoxidizers. The term fuel binder as used throughout this invention notonly includes the polymeric composition which is present in a majoramount but also includes a minor amount of one or more curing agentsused in the resin art which imparts the required rigidity or body to thefinal useable gas generating composition. Because the curing agent willvary according to the polymer or polymers being treated, the amount ofcuring agent or agents used cannot be stated with preci- SlOIl.

Fuel binders containing substantial quantities of oxygen in the moleculeare favored in order to maximize the amount of available gaseousproducts and to assist in the oxidation of the binder. Among the manyfavored oxygen containing resins which can be used are the following:The polyamides, the polyesters the polycarbonates, the polyurethanes,the polyacrylates, the polyepoxides as well as these resins modified bynitration and the like or these resins copolymerized with other resinsor each other. While the polysulfides, polyalkylenes and othernon-oxygen containing polymeric binders can be utilized for gasgenerating composiitons their use is not particularly favored becausethey tend to evolve a significant amount of solid particles duringcombustion.

A group of fuel binders that are especially preferred because of theirsuperior physical and combustion characteristics, are the polyesters,particularly the carboxy-terminated linear polyesters having a molecularweight ranging from 500 to 5000.

Where the preferred carboxy-terminated linear polyesters are used asfuel binders, the polyester can be prepared by reacting a polycarboxylicacid with a hydroxylated, preferably polyhydroxylated, compound underreaction conditions such as temperature, pressure and catalystsdescribed in the resin art. The reaction product is a liquidcarboxyterminated prepolymer which is admixed with other components ofthe composition and cured to form the final gas generating composition.

Typical polycarboxylic acids which can be used as reactants in preparingthe above described carboxy-terminated polyesters include oxalic,adipic, sebacic, maleic, fumaric, and others as well as mixtures ofthese acids. Hydroxylated reactants include, among others the glycolssuch as; ethylene glycol, diethylene glycol, propylene glycolpolybutylene and polypropylene glycols, glycerols, sorbitols, castoroil, 1,2,641exane triol and the like as well as mixtures of thesecompounds and their analogues. In the alternative any of the numerouscommercially available polyesters can be used as the source of the fuelbinder.

Similarly where the binder is to be polyurethane based, the polyurethanecan be made by reacting an organic isocyanate or diisocyanate with oneor more polyols, polyethers, polyesters, or other hydroxylated materialsin the presence of a suitable base such as an amine. Alternatively thepolyurethane binder can be derived by curing commercially availablepolymers or their mixtures.

Whereas ordinarily the fuel binders contemplated are a single polymer,such as the polyacrylamides, the polyurethanes, the polysulfides, andthe like, frequently it is advantageous to prepare mixtures of theseresins or the resins modified by imparting additional functional groupsto the resinous molecule. For example, a modified polyurethane resin canbe prepared reacting a polyurethane with 1,2-ethane dithiol to result ina prepolymer which can be cured by the polysulfide type of cure. Anotherapproach to the same type of prepolymer is to react a carboxy-terminatedpolyester with the 1,2-ethane dithiol.

In all instances, the resin used as a fuel binder is cured according tothe curing techniques well known to the particular resin art using theusual polymerization catalysts, curing agents or accelerators commonlyused. For example, the polyesters are cured at temperatures ranging from80l80 F. and above, using the usual curing agents such as polyimines,polyepoxides, and the like. Similarly, the polyurethane prepolymers canbe cured at temperatures varying between ambient and 200 F. and evenhigher when treated with curing agents such as polyols. Both thepolysulfides and the mercaptan-terminated polyurethanes are cured attemperatures ranging from 120 200 F. using peroxide curing agents suchas benzoyl peroxide. Since the methods of preparing or modifying thevarious resins used as binders are not the novel feature of thisinvention no attempt is made to describe these manipulations in detail.It shall sulhce to say that the preparative methods and curingtechniques are well known procedures described in the technicalliterature particularly in the Plastics Application Series published byReinhold Publishing Corporation, New York City, New York.

(3 PROPELLANT ADJ UVANTS In addition to the curing agents, solvents,polymerization and vulcanization catalysts and the like which areincluded within the fuel binder content of the inventive gas generatingcompositions, certain conditioning or modifying agents can often be[advantageous] advantageously added to gas-generating compositions toalter or improve their physical and combustion characteristics. For[convenience] cvnveniences sake, these substances are herein genericallyreferred to as propellant adjuvants and they can be present in thefinished gas generating composition in amounts from up to about 10 partsby weight down to part by weight of the final gas generatingcomposition.

More commonly however, the adjuvants comprise from about 025 part byweight or even less up to about 5 parts by weight of the gas generatingcomposition. Among the many propellant adjuvants which can be used areincluded the following typical materials: Plasticizers such as thealkylphthalates and the like, and darkening agents such as carbon. blackor lamp black, ballistic agents such as potassium sulfate,hydroscopicity inhibitors such as dinitrotoluene and various combustioncatalysts. The combustion catalysts are of diverse structure butgenerally are compounds containing oxygen. These catalysts can beinorganic or organic compounds. They include, among many others, oxides,such as magnesium, iron, copper, titanium, calcium, molybdenum, andvanadium oxides and the like. Especially effective as combustioncatalysts are the [chomatcs] chromates and dichromates, generally withammonium dichromate being a preferred catalyst. Other satisfactorycombustion catalysts include metallo organics such as iron and cobaltdicyclopentadienyl, and ferric and cobalt acetyl acetonate and certaindyes including copper phthalocyanine. Organics such as nitrocellulosecan also be elfectively used.

(4) PREFERRED GAS-GENERATING COMPOSITIONS As indicated supra, forvarious reasons, certain individual components of the gas-generatingcompositions are preferred over others. Thus the preferredgas-generating compositions of this invention are made up of hydroxylammonium oxalate combined with:

(1) From about 20 []75% by weight of ammonium perchlorate oxidizer.

(2) From about 15-35% by weight of a carboxy-terminated linear polyesterfuel binder.

(3) From about 0-l0% by weight of a propellant adjuvant.

(S) COMPOUNDING THE INGREDIENTS In preparing the solid gas generatingcomposition the following procedure among many others can be used.

The dried oxidizer such as a perchlorate (20-80 parts by weight) isreduced to a finely divided condition by grinding or some other means.From about [20]I060 parts by weight of hydroxylammonium oxalate and fromabout l5-35 parts by weight of combustible fuel binder, either preparedearlier from the reactants, or as the commercially available monomer orpolymer is placed in a blending vessel equipped with an efiicient sparkproof mixer and the fine particles of the oxidizer are added thereto.

Also added at this time are O-10 parts by weight of any propellantadjuvants that are required. During these additions efficient mixing ismaintained until a homogeneous mixture results. The total mixing timenecessary for a uniform mixture varies according to the batch size butordinarily at least 30 minutes of mixing is required with minutes ormore representing the extreme time. Finally the curing agent or agentswhere necessary are added and the mixing continued for an additional /2to 1 hour. Finally the [uniformally] uniformly blended unculred gasgenerating composition is cast into a gas generator engine and thecomposition is cured at the required temperature until the desiredhardness is obtained. The curing times and temperatures are dependentupon the particular resin used as a binder, and the batch size amongother things and thus cannot be stated with precision. However, thefollowing ranges of time and temperature are typical for curing gasgenerating compositions containing the fuel binders described below.

In order to illustrate the preparation and use of the novel gasgenerating compositions of this invention, the following examples aresubmitted.

7 Example 1.-Preparation of ammonium perchlorate-based gas generatingcomposition using hydroxyl ammonium oxalate acid as coolant Thecombustible fuel binder used in this formulation is a polyester resinprepared by condensing 9.4 moles of adipic acid with 8.94 moles ofdiethylene glycol. The resulting polyester has an acid number of 60 anda viscosity of 90 poises at 27 C.

To a suitable blending vessel fitted with a vertical planetary mixer isadded 21.48 parts by weight of the above polyester, 2.0 parts by weightof ammonium dichromate combustion catalyst and 28.0 parts by weight ofhydroxyl ammonium oxalate. These components are mixed for 10 minutes,then 45 parts by weight of ammonium perchlorate oxidizer are added andthe resultant blend mixed for an additional 30 minutes. At the end ofthis time, a curing system comprising 1.42 parts by weight oftris[l-(2-methyl)aziridinyl]ph0sphine oxide and 2.l parts by weight of1,1'-(sulfonyldiethylene)bis-2-methylaziridine is added and the mixturestirred for an additional 20 minutes. The flame temperature of thecombustion is determined by casting a representative sample of the gasgenerating composition in a gas generator engine and curing at 135 F.for 24 hours. The flame temperature measured with a thermocouple duringthe engine firing is found to be about 1850 F.

Example 2.-Preparation of the ammonium perchloratebased gas-generatingcomposition of Example 1 without hydroxyl ammonium oxalate coolant Inthis example substantially the same formulation is used as described inExample 1. However, to indicate the critical role that the inclusion ofthe coolant into the propellant composition plays in the conversion of atypical propellant composition to a gas-generating composition, thehydroxyl ammonium oxalate in the formulation of Example 1 is replacedwith an additional 28 parts by weight of ammonium perchlorate oxidizer.The equipment blending techniques and binder preparation are asdescribed in Example 1.

To a suitable blending vessel fitted with a vertical planetary mixer isadded 21.48 parts by weight of the polyester described in Example 1, 2.0parts by weight of ammonium dichromate combustion catalyst, and 73.0parts by weight of ammonium perchlorate. The components are mixedvigorously for 30 minutes. At the end of this time a curing systemcomprising 1.42 parts by weight of tris[l-(2-methyl)aziridinyl]phosphine oxide and 2.10 parts by weight ofl,l'-(sulfonyldiethylene)bis-2- methylaziridine are added and themixture is stirred for an additional 30 minutes. A cured sample isprepared as described in Example 1 and the flame temperature measured inthe same manner. The flame temperature during combustion is found to beat about 3500 F.

As the 1700 F. difference in flame temperature between the compositionsof Example 1 and Example 2 indicates, the addition of hydroxyl ammoniumoxalate coolant to the propellant composition substantially lowers flametemperature and makes the use of a typical perchlorate-based propellantas a gas-generating composition possible.

Example 3.Preparation of a gas-generating composition using lesser andgreater quantities of hydroxyl ammonium oxalate coolant In this exampletwo formulations are prepared substantially as described in Example 1.The binder (including the same curing agents), oxidizer, and combustioncatalysts and techniques are the same as previously described. In thefirst formulation the amount of hydroxyl ammonium coolant is reduced to15% by weight largely by increasing the amount of ammonium perchloratein the composition. In the second formulation the hydroxyl ammoniumoxalate content is increased to 40% by weight at the expense of theammonium perchlorate content.

Both formulations are cast and cured at F. for 24 hours. The flametemperatures are measured as described in Example 1. The flametemperatures of both formulations are less than 2500 F.

Examples 4-6.Preparation of the formulation of Example 1 using otherperchlorates In these examples the same polyester fuel binder, hydroxylammonium oxalate coolant and ammonium dichromate combustion catalystdescribed in Example 1 are used. The same quantities of these compoundsare used and the identical blending techniques and procedures used inExample 1 are followed. The sole difference being that in each instance28 parts by weight of the indicated perchlorate replaces ammoniumperchlorate in the gasgenerating composition on a weight by weightbasis.

Example Number Perchlorate Oxidizor Flame Temperature 4 l Sodium Lessthan 3,00() 1*.

.. Potassium Do. Lithium 1J0.

Examples 7-10.Preparation of gas-generating compositions using variouscombustion catalysts Using the ammonium perchlorate oxidizer, thepolyester binder and the hydroxyl ammonium oxalate coolant described inExample 1, comparable gas generating compositions are prepared exceptthat the following combustion catalysts are substituted for ammoniumdichromate on a weight by weight basis.

Example number: Combustion catalyst 7 2% by weight ferric oxide.

8 2% by weight cobalt oxide.

9 2% by weight nitrocellulose.

l0 2% by weight cobalt acetyl acetonate.

In each instance, smooth combustion is observed.

Example ll.Preparation of another gas-generating composition utilizing apolyester-polyurethane binder The binder used in this example is of thepolyesterpolyurethane type. The particular binder or closely analogousbinders are available commercially or can be prepared as describedbelow.

The polyester is obtained by condensing 8.3 moles of adipic acid with9.3 moles of diethylene glycol. The resulting condensate is treated with2 moles of 2,4-toluene diisocyanate for 3 hours at 180 F. The isocyanate(NCO) content of the uncured polyester-polyurethane binder is found tobe 3.6% by weight.

The gas generating composition is prepared by adding 14.4 parts byWeight of the above binder, 2.0 parts by weight of ammonium dichromatecombustion catalyst and 28.0 parts by weight of hydroxyl ammoniumoxalate coolant to a suitable reactor fitted with a vertical planetarymixer. After the charge has mixed for 10 minutes, 45 parts by weight ofammonium perchlorate oxidizer is added and the mixing is continued foran additional 30 minutes. Another 10.6 parts by weight portion of thepolyesterpolyurethane binder is added and the charge mixed for anadditional 20 minutes to assure the homo geniety of formulation.

A sample of the composition is cast in an engine and cured at 135 F. for16 hours. A fiame temperature of approximately 2150 F. is obtained.

Example 12.Preparation of another gas-generating composition using athiol-terminated binder The binder used in this example is amodification of the polyester-polyurethane binder used in Example 11.One mole of the binder of Example 11 is treated with 2 moles of1,2-ethane dithiol to produce a thiol-terminated binder. These bindersare advantageous because of their ease of curing. Again, all equipment,blending techniques and measurements are made as described in Example 1.

A vertical planetary mixer is charged with 23.15 parts by weight of theabove binder, 2.0 parts by weight of ammonium dichromate combustioncatalyst, 1.85 parts by weight of p-quinone dioxime curing agent and28.0 parts by weight of hydroxyl ammonium oxalate coolant. The charge isthoroughly mixed for minutes, at which time 45 parts by weight ofammonium perchlorate oxidizer is added and the mixing is continued foran additional 45 minutes.

A strand sample of the above composition is cured at 170 F. for 48 hoursin an oven. A flame temperature of about 1800 F. is observed.

Having thus described my hydroxyl ammonium oxalate coolant and its usein gas-generating composition, I claim my invention as follows:

1. A curable homogenous gas-generating composition composed essentiallyof from about 1060% by weight of hydroxyl ammonium oxalate coolantcombined with:

(1) from about 20[80]75% by Weight of perchlorate oxidizer selected fromthe group consisting of ammonium perchlorate, the alkali metalperchlorates and the alkaline earth metal perchlorates,

(2) from about -35% by weight of combustible fuel binder,

(3) from about 010% by weight of a propellant adjuvant.

2. The composition of claim 1 wherein (1) the oxidizer is ammoniumperchlorate.

3. The composition of claim 1 wherein (1) the oxidizer is sodiumperchlorate.

4. The composition of claim 1 wherein (1) the oxidizer is potassiumperchlorate.

5. The composition of claim 1 wherein (l) the oxidizer is lithiumperchlorate.

6. The composition of claim 1 wherein (2) the combustible fuel binder isa polyester resin.

7. The composition of claim 1 wherein (2) the combustible fuel binder ispolyester-polyurethane.

8. The composition of claim 1 wherein (2) the combustible fuel binder isa carboxy terminated linear polyester.

9. The composition of claim 1 wherein (3) the propellant adjuvant isammonium dichromate.

10. The composition of claim 1 wherein (3) the propellant adjuvant isferric oxide.

11. The composition of claim 1 wherein (3) the propellant adjuvant iscobaltic oxide.

12. The composition of claim 1 wherein (3) the propellant adjuvant isnitrocellulose.

13. The composition of claim 1 wherein (3) the propellant adjuvant iscobalt acetyl acetonate.

14. A curable homogeneous gas-generating composition composedessentially of from about [20]I060% by weight of hydroxyl ammoniumoxalate combined with:

(1) from about 20[80]75% by weight of ammonium perchlorate oxidizer,

(2) from 15-35% by weight of a polyester fuel binder,

and

(3) from about 0-5 "/0 by weight of ammonium dichromate.

15. The composition of claim 14 wherein (Z) the polyester binder is ofthe polyester-urethane type.

16. The composition of claim 14 wherein the polyester binder is a thiolterminated polyester-urethane.

17. The composition of claim 14 wherein the polyester fuel binder is acarboxy terminated linear polyester.

18. The method of preparing a cured gas-generating composition whichcomprises mixing:

(1) from about 20[80]75% by weight of perchlorate oxidizer selected fromthe group consisting of ammonium perchlorate, the alkali metalperchlorate, and the alkaline earth metal perchlorates,

(2) from about 15-35% by weight of a combustible fuel binder includingcuring agents,

(3) from about [20]10-60% by weight of hydroxyl ammonium oxalatecoolant, and

(4) from about 0l0% by weight of a propellant adjuvant, and casting theresultant mixture into a desired configuration and curing said mixtureinto a cured gas-gencratirig composition.

19. The method of claim 18 wherein (2) the combustible fuel binder is apolyester.

20. The method of claim 18 wherein (Z) the combustible fuel binder is acarboxy terminated linear polyester.

21. The method of claim 18 wherein the combustible fuel binder is athiol terminated polyester-polyurethane.

22. The method of claim 18 wherein the combustible fuel binder is apolyester-polyurethane.

23. A method of reducing the flame temperature of perchlorate basedgas-generating compositions comprising incorporating: 10-6D parts byweight of hydroxyl ammonium oxalate into each parts of thegas-generating composition, said gas generating composition composedessentially of: combustible fuel binder, perchlorate oxidizer andpropellant adjuvants.

24. The method of claim 23 wherein the combustible fuel binder is apolyester binder.

References Cited 10/1961 Barr l4983 X 1/1963 Doe et al l4919 BENJAMIN R.PADGETT, Primary Examiner.

